Euro 7 The Evolution of Emission Legislation in Europe

It has been 30 years since the first Euro emission legislation (Euro 1 in 1992). In successive revisions of the legislation, the limits have tightened, new pollutants have been included and test conditions have evolved to the point where the focus of legislation is now on the measurement of emission during on-road operation. This means that we are now testing real-world emissions and avoiding “cycle beating” where emissions are optimized for pre-defined cycles under laboratory test conditions but are often much worse during normal driving.

Euro 7 can be seen as the ultimate in emissions legislation in terms of three key factors:

• Low limits on a wide range of pollutants (“near zero emissions”)
• Very wide test conditions covering almost all areas of operation (“under all conditions”)
• Significant increases in durability durations (“for full useful life”)

Limits for all Euro 7 light-duty vehicles have been set at the level of gasoline limits for Euro 6, on the basis that internal combustion engine bans coming in during the 2030s will mean that Euro 7 vehicles will have a limited market window. Although this appears to be a very small improvement, several factors in Euro 7 are effectively lowering limits further, including the following:

• Widening of test conditions, making it harder to meet limits (especially at very low temperatures)
• Removing ‘conformity factors,’ which allow for the reduced accuracy of portable emissions measurement systems used in real driving emissions tests
• Adding nanoparticles down to 10nm (PN₁₀) to the measurement of particulate number
• Increasing emissions durability duration

Limits for Euro 7 heavy-duty vehicles, where the internal combustion engine is seen as the primary power unit for several decades to come, are reduced significantly from Euro 6 levels. Wider test conditions, removal of conformity factors and the change to PN₁₀ also add to the compliance challenges. The emissions durability duration for heavy-duty vehicles will be 875,000km, a significant increase from the 700,000km of Euro 6.

With the growth of the electric vehicle market, it is very possible that Euro 7 could be the last major piece of emission legislation in Europe. The legislation should significantly improve air quality across Europe, especially in the pollution hot spots within major cities. High performance fuels and lubricants will be key enablers of these improvements.